staging/easycap: Kill leftover build options in readme

The following options were removed from in-tree driver, but were left
in README:

- EASYCAP_IS_VIDEODEV_CLIENT was removed in cb81fa07 (staging/easycap:
  kill EASYCAP_IS_VIDEODEV_CLIENT compilation conditional);

- EASYCAP_NEEDS_V4L2_DEVICE_H/EASYCAP_NEEDS_V4L2_FOPS were removed in
  30516058 (staging/easycap: kill EASYCAP_NEEDS_V4L2_DEVICE_H and
  EASYCAP_NEEDS_V4L2_FOPS);

- EASYCAP_NEEDS_UNLOCKED_IOCTL was removed in f2b3c685 (staging/easycap:
  kill EASYCAP_NEEDS_UNLOCKED_IOCTL).

Remove them.

Cc: Mike Thomas <rmthomas@sciolus.org>
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/easycap/README

@@ -27,28 +27,6 @@ BUILD OPTIONS AND DEPENDENCIES
 Unless EASYCAP_DEBUG is defined during compilation it will not be possible
 to select a debug level at the time of module installation.
 
-If the parameter EASYCAP_IS_VIDEODEV_CLIENT is undefined during compilation
-the built module is entirely independent of the videodev module, and when
-the EasyCAP is physically plugged into a USB port the special files
-/dev/easycap0 and /dev/easysnd1 are created as video and sound sources
-respectively.
-
-If the parameter EASYCAP_IS_VIDEODEV_CLIENT is defined during compilation
-the built easycap module is configured to register with the videodev module,
-in which case the special files created when the EasyCAP is plugged in are
-/dev/video0 and /dev/easysnd0.
-
-During in-tree builds the following should should be defined whenever the
-parameter EASYCAP_IS_VIDEODEV_CLIENT is defined:
-
-EASYCAP_NEEDS_V4L2_DEVICE_H
-EASYCAP_NEEDS_V4L2_FOPS
-EASYCAP_NEEDS_UNLOCKED_IOCTL
-
-If the build is performed out-of-tree against older kernels the parameters
-to be defined depend on the kernel version in a way which will not be
-discussed here.
-
 
 KNOWN RUNTIME ISSUES
 --------------------